Manufacture or treatment of textile materials



Patented Apr. 16, 1940 7 MANUFACTURE OR TREATMENT OF TEXTILE MATERIALS I Henry Dreyfus, London, England No Drawing. Application September 18, 1936,

Serial No. 101,427. 3, 1935 3 Claims.

This invention relates to the manufacture and treatment of textile materials comprising voluminous artificial threads, i. e. threads having a crimpy or curly character such as may be produced, for instance, by the processes described in Patents Nos. 2,089,198, 2,089,199 and 2,111,211 and British Patents Nos. 459,781 and 474,401.

Fabrics made from such threads share with fabrics of natural crimpy fibres, for example wool or cotton, certain valuable features, in particular a high degree of softness and good heat insulating properties. These valuable properties are largely due to the voluminous nature of the threads, for which in turn the crimpy or curly character of the filaments of the threads is mainly responsible. If these valuable properties are to be obtained in the highest measure, it is essential that the crimpy character of the filaments and therefore the voluminous character of the threads should be retained to the utmost, and that the fabric-forming operation should not be conducted in such a way as to reduce materially the degree of crimp initially present.

Unfortunately, fabric-forming operationsnecessarily involve subjecting the threads to a certain amount of tension. It has been found that this tension tends to reduce the degree of crimp of the filaments of the threads, with the result that the fabrics obtained have not the softness and heat insulating properties which could reasonably be expected from the voluminous nature of the threads prior to fabric-formation.

According to the present invention, the tendency of voluminous artificial threads to lose their voluminous character during operations in which they are subjected to tension, e. g. the operations involved in forming the threads into fabric, is reduced or eliminated by providing the threads with a dressing of a film-forming substance, preferably of elastic properties. By film-forming substance is meant a substance which yields a film when the solvent is removed from a thin layer of a solution thereof. By dressing the threads in this manner, threads are obtained in which the filaments adhere one to another and to which considerable tension may be applied without substantial removal of the voluminous character of the thread. Threads so dressed may therefore be woven or knitted into fabrics, and a product containingfilaments of substantially the same degree of crimp as the filaments of the initial thread may be obtained.

Preferably the film-forming substance employed is one which is readily removable from the threads after the fabric has been formed, for instance by water or an alkaline solution.

The process of the invention is applicable to various kinds of thread containing crimped artificial filaments. For example the crimpy fila- In Great Britain October ments may be substantially continuous, or they may be discontinuous as in staple fibre threads. Again, they may be made of various materials, for example of regenerated cellulose, e. g. cellulose regenerated from viscous or cuprammonium or other solutions, or of cellulose acetate or other cellulose esters or ethers.

The" threads comprising crimpy or curly filaments may have been made in any desired manner. For example, the threads may be those obtained by setting twist in a thread and subsequently removing twist, as described, for instance, in U. S. Patent No. 2,089,198. According to that specification the twist is set in threads while they are travelling, and is then subsequently removed, preferably also while the thread is travelling. Again, the threads may be those made in the manner described in U. S. Patent No. 2,089,199, namely by twisting a thread while simultaneously applying a setting medium and subsequently detwisting the twisted and set thread. Another type of thread to which the process is applicable is one comprising filaments contained in the manner described in British Patent No. 459,781, namely by spinning cellulose ester or ether filaments containing p-dichlorbenzene or other similarly acting substance, and thereafter subjecting the filaments to the action of hot aqueous media. The thread employed in the process of the invention may also be prepared by the process of British Patent No. 474,401, in which a voluminous 1 thread, prepared for instance by one of the processes described in U. S. Patents Nos. 2,089,198, 2,089199 and 2,111,211, is treated with a hot aqueous medium. The present invention is not, however, restricted to the working up of threads prepared in the manners particularised above, as it may be applied in the case of threads containing crimpy filaments prepared by other means, for example by the passage of filaments between pairs of fluted rollers or by subjecting filaments to the action of crinkling agents.

The film-forming substances to be employed in accordance with the present invention may be natural or synthetic resins orother substances of high molecular weight, for instance rubber, waxes and higher aliphatic acids such as stearic acid and their derivatives. Preferably the film-forming substance employed has a non-brittle and elastic character. The amount of film-forming substance applied to the threads may be from 1 less than 1 up to 5, 10 or 20% of the weight of the threads, or even more, for instance up to 30, 40 or of the weight of the threads.

An important class of film-forming substances suitable for the invention is the class of polymerization products of polymerisable unsaturated organic compounds, for example polymerised vinyl compounds. Particular mention may be made of polymerisation products of vinyl compounds containing the' group linked to oxygen as in a vinyl ether or ester, or to a negative group, for example a carboxylic group or carboxylic ester group or an aromatic nucleus. As examples of such polymerised vinyl compounds may be mentioned polymerised vinyl esters, e. g. polyvinyl acetate, polymerised vinyl ethers, and polymerised esters of acrylic acid or other acids of the acrylic series, e. g. methacrylic acid. When polyvinyl acetate is employed, the amount applied to the threads is preferably between 0.2 and 5%, e. g. 0.4 or 0.5 to 1 or 2%, of their weight.

Another type of film-forming substance especially suitable for the purpose of the present invention is a resin of the alkyd type, by which term is meant a resinous product obtainable from a dior poly-basic acid and a dior poly-hydric alcohol. Typical of'this class of body are the products obtainable by heating phthalic anhydride with glycerine. Particularly useful are rubbery or plastic products obtainable by discontinuing the reactions before brittle products or products of very high molecular weight have been formed.

Cellulose esters or ethers, for example a cellulose acetate of low viscosity, are also film-forming substances suitable for use in the case of certain types of artificial filaments.

It is, however, particularly advantageous to utilise film-forming substances which are soluble in water or in aqueous liquids. Such filmforming substances possess important advantages both as regards ease of application to the threads containing the crimped filaments and as regards ease of removal from the woven or otherwise formed fabric. Thus, they may be applied in the form of aqueous solutions and removed from the fabrics by aqueous scouring treatments and so do not necessitate the use of organic solvents, as is the case when certain of the above-mentioned film-forming substances are employed.

Where saponifiable film-forming substances are employed, they may be removed by saponifying, for instance, by treatment with alkali solution, and then removing the saponification products. Thus, polymerised vinyl acetate may be removed from the fabrics in this manner. When such saponifiable substances have been employed with threads of cellulose acetate or other organic esters of cellulose, the saponification treatment may or may not be effected so as to result in saponification of the cellulose esters present as well as of the film-forming substance.

If only a small quantity of the film-forming substance is applied to the threads, it may not be necessary to remove the substance from the formed fabric.

The following are examples of substances soluble in water or aqueous liquids which may be used for the purposes of the invention:

(a) Film-forming carbohydrates, particularly celluloses, soluble in water or in water containing a small proportion of alkali, for example, B-cellulose, v-cellulose or other degraded celluloses which are more or less soluble in dilute aqueous alkalies or water. be those prepared by direct degradation of cellulose, for example, by treatment with alkalies or acids, e. g. by treating with dilute or concentrated caustic soda or by the action of sulphuric Such celluloses may.

acid. They may also be those prepared by degrading a suitable cellulose derivative and subsequently regenerating cellulose from the degraded product. For example, cellulose may be regenerated from a viscose solution which has been ripened to a degree very considerably beyond that of the viscose solutions normally used for spinning artificial filaments. Again, cellulose acetate may be ripened until soluble in dilute alcohol and then saponified.

(b) Film-forming carbohydrate esters or ethers soluble in wateror aqueous liquids, particularly cellulose esters or ethers having the property of dissolving in water or aqueous liquids owing to the degree of degradation of the cellulose molecule and/or the presence, in esterifying acid radicles or in ether radicles, of hydrophile groups for example hydroxyl groups or acid or basic groups, e. g. amino groups, carboxy groups or sulphonic groups. There may be utilised for instance the cellulose esters or ethers which have been ripened so that they are soluble in dilute acetone, dilute alcohol, or water, or the cellulose esters referred to in U. S. Patent No. 1,950,664, and obtainable by esterifying cellulose, e. g. in the presence of chloroacetic anhydride with dicarboxylic acids, for example oxalic acid or maleic acid, or obtainable by subjecting cellulose acetate to the action of a hydroxy carboxylic acid e. g. glycollic acid, lactic acid, malic acid, mandelic acid, tartaric acid, or a glyceric acid, so as to replace acetic acid residues by hydroxy-acidyl or carboxy-acidyl residues. Again, there may be utilised the cellulose ethers referred to in U. S. Patent No. 1,950,664, and in which the cellulose is etherified so as to contain residues of glycols or other polyhydric alcohols, for example by the action of ethylene oxide or other alkylene oxide or in the manner described in U. S. Patent No. 1,502,379, and British Patent No. 277,721, or in which the cellulose is etherified with carboxy-alkyl groups, for example by treating alkali cellulose with chloroacetic acid, in the manner described in U. S. Patent No. 1,884,629 so as to produce cellulose derivatives containing 1 A-2 or more carboxy methyl ether groups per C6H10O5 molecule. Cellulose carboxy-methyl ethers soluble in dilute aqueous ammonia are especially useful.

(0) Polymerised vinyl compounds containing hydroxy or other groups of hydrophile charac-' merised vinyl acetate or other polymerised vinyl ester in the manner described in British Patent No. 454,425. The polyvinyl compounds containing hydrophile groups described in my prior U. S. Patent No. 2,145,345, may also be employed.

(d) Polymerised esters of acrylic acid or other acids of the acrylic series which have been wholly 7 or partly saponified so as to render them soluble in water or water containing a small proportion of alkali.

(e) Resins of the alkyd type prepared from hydroxy dior poly-carboxylic acids and di- 7 or poly-hydric alcohols as described in U. S. application S. No'. 67,149, filed March 4, 1936.

(j) Film-forming substances of the albumen type, for example casein or gelatine. Casein may readily be dissolved in water containing a small amount of alkali, for example ammonia.

Particularly useful for the invention are those film-forming substances which, though insoluble in water, dissolve in water containing very small amounts of alkali, particularly those soluble in water containing a little ammonia. By acidification of the dressed material or by simple heating in the case of solutions prepared with ammonia, the film-forming substance may be converted into a water-insoluble form which is of considerable resistance to the action ofwater. In spite of this, however, the film-form ing substance is readily removed from the finished fabrics by scouring in an aqueous bath containing a small amount of ammonia or other suitable alkali.

The dressing with the film-forming substance is conveniently effected by the application of a solution of the film-forming substance followed by drying'in order to evaporate solvent and/or to render the film insoluble in water as when employing ammoniacal solutions of casein or other film-forming substance. The film-forming substance may be used in conjunction with other materials, for example lubricants or softening agents. Such additional agents, for example soaps or higher fatty acids, may serve not only to modify the'mechanical properties of the dressing but also to render it more easily removable from the materials by a scouring operation.

The actual application of the dressings is conveniently effected by passing the threads through suitable solutions of the film-forming substances and subsequently drying. It is important that the threads shall be subjected to as little tension as possible until the film-forming substance has been applied to and dried on the threads. Spraying the travelling threads with the solutions of 'the film-forming substance is another method of application which may be used. If desired the dressing may be effected continuously with an operation involved in the production of the threads containing crimped filaments. For example in the case of one of the crimping processes described in U. S. Patents Nos. 2,089,198, 2,089,- 199 and 2,111,211, the issuing thread may be dressed with the film-forming substance prior to winding.

The dressed threads may be worked up into fabrics in any desired manner but the invention is of particular utility in the case of producing knitted fabrics. After the fabric-forming operation the fabrics may be subjected to a treatment to remove the film-forming dressing, thus leaving fabrics containing filaments having substantially the same degree of crimpiness as the initial threads from which the fabrics have been made. This removal may be effected in any desired manner, the method in any particular case depending, of course, upon the nature of the film-forming substance which has been employed. For example, an aqueous scouring treatment may be used where suitable, or an extraction with an organic solvent in the case of film-forming substances which are insoluble in aqueous liquids but whichare soluble in an appropriate organic solvent.

The invention is illustrated by examples:

the following Example, 1

voluminous cellulose acetate yarn is treated Example 2 Cellulose acetate yarn is crimped by the process of U. S. Patent No. 2,089,198, and is drawn continuously through a bath containing a 10% so-' lution of a polymerisation product of the methyl ester of acrylic acid, such as the product sold under the registered trade-mark Plextol A, in a solvent mixture consisting of 40 parts of benzene, 40 parts of toluene and 20 parts of acetone by volume, The dressing is then dried on the yarn.

The yarn is woven or knitted, and the fabric formed is treated with the solvent mixture specified above to remove the dressing.

Example 3 A crimped regenerated cellulose yarn is drawn continuously through a bath containing an aqueous solution of the product obtained by saponifying polyvinyl acetate in the manner described in British Patent No. 454,425. After leaving the baththe yarn is dried on steam heated rollers, collected, and' subsequently woven or knitted into fabric.

After formation of the fabric the dressing is removed by scouring the fabric in an aqueous liquid containing a soap.

In a similar way other film-forming substances can be applied to yarns, e. g. water-soluble methyl cellulose, gelatin or other of the carbohydrate derivatives or albuminous substances specified above.

Having now described my invention, what I desire to secure by Letters Patent is:

1. In the production of knitted fabrics from artificial yarn, the steps of crinkling yarn of an organic ester of cellulose containing para-dichlorbenzene as plasticizer by ahot aqueous treatment, and coating said crinkled yarn before knitting with a synthetic resin which is a polymerizate of an unsaturated oxygen-containing compound so as to reduce the tendency of the yarn to lose its voluminous character when subjected to tensions involved in knitting.

2. In the production of knitted fabrics from artificial yarn, the steps of crinkling yarn of cellulose acetate containing para-dichlorbenzene as plasticizer by a hot aqueous treatment, and coating said crinkled yarn before knitting with a synthetic resin which is a polmerizate of an unsaturated oxygen-containing compound so as to reduce the tendency of the yarn to lose its voluminous character when subjected to tensions involved in knitting.

3. In the production of knitted fabrics from artificial yarn, the steps of crinkling yarn of cellulose acetate containing para-dichlorbenzene as plasticizer by a hot aqueous treatment, and coatjected to tensions involved in knitting.

HENRY DREYF'US. 

